Shiur #12: An Oath Concerning Half a Measure of a Prohibited item

  • Rav Shmuel Shimoni
Sources: In the next shiur we will examine the view of Resh Lakish who understood the Mishna as referring to an oath concerning half a measure. We must consider whether his explanation is possible even according to Rabbi Yochanan who says that the prohibition of half a measure is by Torah law, and if so, why.
 
1. Review Resh Lakish's understanding of the Mishna: 23b from the colon at the bottom to 24a, "ela le-korban"; Yoma 73b in the Mishna until "u-bi-shetiya" and in the Gemara until 74a, "lav bar hagada hu kelal," and Rashi, ad loc., 74a, s.v. ve-aliba.
 
2. Rashba, 23b, s.v. ha de-amrinan; Rambam, Hilkhot Shevuot 5:7 and beginning of 8 and Radbaz on both of them; Tosafot 22b, s.v. a-hetera; Tosafot 23b, s.v. de-moki. Consider the similarities and the differences between the Tosafot and the Rambam; Ritva 22b, s.v. o dilma da'atei, "ve-ha de-mashma de-lo mitsarve-zeh ikar; Chiddushei ha-Ran 23b, s.v. de-mokim.
 
*********************************************************
 
I. Are we bound by an oath from Mount Sinai not to eat half a measure of a prohibited item? The plain meaning of the passage in Shevuot
 
In the previous shiurim we dealt with the Mishna on p. 22b which imposes liability for breaking an oath with the eating of neveilot or tereifot, and with the question why the limitation of "bound by an oath from Mount Sinai" does not apply in this situation. We focused on the answer given by Rabbi Yochanan, who understood the Mishna as dealing with an inclusive oath, and on Resh Lakish's opposition to this solution. Today we will move on to the answer to this difficulty proposed by Resh Lakish himself, and to Rabbi Yochanan's position regarding this solution. The Gemara states as follows (23b):
 
Why? Surely he is bound by an oath from Mount Sinai!...  Resh Lakish said: You cannot solve [this problem] except either if he expressly prohibits half the legal measure, in accordance with the view of the Rabbis; or, if his oath is undefined, in accordance with the view of Rabbi Akiba, who says, a man [in an undefined oath] prohibits to himself even a minute quantity. Granted, R. Yochanan does not agree with Resh Lakish, because he wishes to expound our Mishnah in accordance with the views of all… Granted, according to Resh Lakish, it is for this reason that Rabbi Shimon exempts him; for we learned: Rabbi Shimon says: A minute quantity [imposes liability] for lashes; and it was not said that an olive-sized measure is necessary except for [imposing liability for] a sacrifice.
 
What follows from the plain meaning of our passage is that according to Resh Lakish there is no problem of "bound by an oath from Mount Sinai" with respect to half a measure of the prohibition of neveila. Therefore, when a person takes an oath not to eat a half-olive sized measure of neveila, his oath takes effect, and according to Rabbi Akiva, even in the case of an undefined oath, where the person swears that he will not eat neveilot, the oath takes effect with respect to half a measure. As may be recalled from shiur no. 4, according to Resh Lakish half a measure is prohibited by Rabbinic decree, whereas according to Rabbi Yochanan it is prohibited by Torah law, but according to the plain meaning of our passage this prohibition of half a measure does not define the situation as one of "bound by an oath from Mount Sinai." This is true even according to Rabbi Yochanan, who does not reject the logic of Resh Lakish's answer, but only his decision to interpret the Mishna accordingly. Only according to Rabbi Shimon, who imposes liability for lashes for less than an olive-sized measure, are we dealing with a prohibition that turns the situation into one of "bound by an oath from Mount Sinai."
 
II. The Passage in Yoma
 
Let us now examine the passage in Yoma, which suggests a different approach to the issue. The Gemara there on p. 73b initially maintains that according to Resh Lakish half a measure is permitted, and then proposes that even according to him, it is prohibited by Rabbinic decree. Here the Gemara objects that if half a measure is prohibited by Rabbinic decree, we should say that even according to Resh Lakish, this should fall into the category of "bound by an oath from Mount Sinai." That is to say, the Gemara's point of departure is the very opposite of that in our passage: Not only if half a measure is prohibited by Torah law would this be a situation of "bound by an oath from Mount Sinai," but this would be the case even if it is only prohibited by Rabbinic decree. Rashi (ad loc.) explains:
 
If Resh Lakish maintains that half a measure is prohibited by Rabbinic law, how does he apply that which is taught that he is liable as referring to a case where he ate half a measure? Surely also with regard to [a half-measure] he is bound by an oath, because of the prohibition of "You shall not turn aside [from what they shall rule for you – lo tasur]" (Devarim 17:11). (74a, s.v. ve-aliba)
 
The Gemara then rejects the assertion regarding Rabbinic prohibitions, and clarifies that they do not fall into the category of "bound by an oath from Mount Sinai." It does not, however, clarify why this is so, or how Rashi's argument regarding the Torah prohibition of lo tasur, which supports Rabbinic decrees, is set aside. The nature of Rabbinic prohibitions is not the focus of our concern today, but nevertheless we will address several points in this context.
 
The Ramban (in his strictures to the Principles in the Rambam's Sefer ha-Mitzvot, Principle 1) maintains that Rabbinic prohibitions do not have the force of Torah law based on the prohibition of lo tasur. His position is not entirely clear, and the Acharonim go on at length in their attempt to explain why we are obligated, according to the Ramban, to listen to the Sages, if God did not command us to do so in His Torah. For our purposes, however, it is clear that, according to the Ramban, it is easy to understand why a Rabbinic prohibition does not fall into the category of "bound by an oath from Mount Sinai." The words of the Ramban were stated in contrast to the position of the Rambam; and the Tashbetz, in his Zohar ha-Raki'a, raises an objection against the Rambam, how does he explain this passage, and why does the rule of "bound by an oath from Mount Sinai" not apply to Rabbinic prohibitions.
 
The author of Megilat Esther on the Rambam's Sefer ha-Mitzvot rejects the words of the Tashbetz, and raises an objection against the Ramban from this passage. The Ramban undoubtedly thinks that it follows from the passage in Yoma when it rejects the initial assumption, that Rabbinic decrees do not have the force of Torah laws. This understanding is difficult in itself, and does not follow from the wording of the Gemara. The Gemara said in its objection: "Resh Lakish agrees that [half a measure] is forbidden by Rabbinic decree. If so, one should be liable on account thereof to offer a sacrifice for an oath!" And in its answer, the Gemara does not state that Rabbinic prohibitions are not included in the category of "You shall not turn aside," but rather: "Since it is permitted by the Torah, [the law relating to the] sacrifice for an oath is operative." From here the Megilat Esther concludes: "It follows from this that he had no doubt that they are included in this prohibition (lo tasur), but rather the uncertainty was whether or not to say about them 'bound by an oath from Mount Sinai.'" Why in fact should we not invoke the rule of "bound by an oath from Mount Sinai" if the prohibition has validity by Torah law?
 
Rabbi Shimon Shkop (Sha'arei Yosher, sha'ar 1, chap. 7) explains that the prohibition that is based on "you shall not turn aside" is not a prohibition of eating, but merely a prohibition of disobeying, and therefore there is no overlap between it and an oath not to eat. It seems to me, however, that this idea explains why there is no limitation here of "a prohibition does not apply to an item that is already prohibited," because the prohibitions do not overlap, but it does not explain why the rule of "bound by an oath from Mount Sinai" does not apply, since the action under discussion is in practice already forbidden to him by Torah law. See the Megilat Esther who expresses this idea in a different manner:
 
Since they were not stated clearly at Sinai, we do not say about them "bound by an oath from Mount Sinai"… even though they are included in the prohibition of "you shall not turn aside," because it would be inappropriate to say about them that they were stated to Moshe at Sinai, since they were not clearly stated…
 
According to him, the rule of "bound by an oath from Mount Sinai" was stated only with respect to commandments the contents of which were established by the Torah. The Sages' authority to issue directives is indeed based on the authorization granted to them by the Torah, but since the Rabbinic decree itself is not commanded by the Torah, from the Torah's perspective we are dealing with an optional matter to which an oath can apply.
 
It should further be noted that according to the position of the Ran, which has already been mentioned and which we will see below, that the rule of "bound by an oath from Mount Sinai" was only stated with regard to something that is explicitly stated in the Torah, there is room to say that Rabbinic prohibitions do not fall into this category. So writes the Radbaz: "The oath pertained only to matters explicitly stated in the Torah. Know that this is true, for it is written in the Torah: 'You shall not turn aside from what they shall rule for you,' but nevertheless an oath applies to a Rabbinic prohibition" (Hilkhot Shevuot 5:7). There is, however, room to question this premise, as it may be argued that this is an explicit prohibition, since the Torah explicitly commands that one may not turn aside from the words of the Sages and the Sages explicitly commanded that one may not eat half a measure. It seems that the Radbaz assumes that we require that the Torah explicitly relate to the specific content of the prohibition, similar to what is argued by the Megilat Esther.
 
In any event, concerning the Torah prohibition of half a measure according to Rabbi Yochanan, it seems clear from the passage in Yoma that this suffices to define the situation as one of "bound by an oath from Mount Sinai"; this, as stated, is in contrast to what follows from the plain sense of the passage in Shevuot. Indeed, the Ramban on our passage notes that there are those who erased the line stating: "Granted, R. Yochanan does not agree with Resh Lakish, because he wishes to expound our Mishnah in accordance with the views of all"; this because Rabbi Yochanan cannot accept Resh Lakish's answer in principle, since half a measure falls into the category of "bound by an oath from Mount Sinai." The Ramban himself does not erase this line; but he explains that the Gemara notes only one reason that Rabbi Yochanan prefers not to resolve the difficulty as did Resh Lakish, alongside other reasons that are true according to him; moreover, in our passage Rabbi Yochanan does not stand alone, but rather together with Rav and Shemuel, whose position on half a measure is not known. The Ramban then clearly adopts the position that follows from the passage in Yoma, that half a measure according to Rabbi Yochanan certainly falls into the category of "bound by an oath from Mount Sinai."
 
In contrast, other Rishonim adopt the position that follows from the plain meaning of our passage, that even though half a measure is prohibited by Torah law according to Rabbi Yochanan,[1] it still does not fall into the category of "bound by an oath from Mount Sinai." We must try to understand their reasoning.
 
III. The Position of the Ran
 
As was already mentioned, the Ran is of the opinion that the rule of "bound by an oath from Mount Sinai" is only valid with respect to commands that are stated explicitly in the Written Law. The Ran says this in several places,[2] one of which is in his Chiddushim to our passage:
 
Even according to Rabbi Yochanan, who says that half a measure is prohibited by Torah law, an oath applies to it, for whatever is not stated explicitly in the Torah as a positive commandment or as a negative commandment, is not called "bound by an oath from Mount Sinai," so that an oath should not apply to it.
 
According to the Ran, it is possible that half a measure is prohibited with the full force of a Torah prohibition, but since it is not spelled out explicitly in the Torah, it does not fall into the category of "bound by an oath from Mount Sinai." This fits in with the plain meaning of our passage, and, as stated above, it goes against the plain meaning of the Gemara in Yoma.[3]
 
The Ran adds that this principle is valid both with regard to an oath to uphold a Torah prohibition and to an oath to transgress a Torah commandment; such an oath apples to prohibitions that are not explicitly stated in the Torah, as they are included in the category of "bound by an oath from Mount Sinai." This is true regarding the prohibition of half a measure, and also regarding the prohibition against causing bodily injury to oneself, which the Ran regards as an example of a Torah prohibition that is not explicitly stated in the Torah. However, argues the Ran, in the latter case, after the oath takes effect, it stands against a valid Torah prohibition, the result being that one is not allowed to fulfill the oath and transgress the Torah prohibition:
 
Since it is not an explicit positive or negative commandment, but rather it is derived by way of a midrashic exposition, an oath applies to it. Not that he should be permitted… even though he took an oath, for even a Rabbinic prohibition sets aside a Torah commandment in a situation of 'sit and do not act,' all the more so a Torah prohibition. For we do not say to a person: Stand up and actively sin in order to fulfill your oath… Here too with half a measure, despite the fact that according to Rabbi Yochanan it is prohibited by Torah law, nevertheless since there is no explicit prohibition, but rather it comes from a midrashic exposition, as is stated in the last chapter of Yoma, if he swore to eat it, but did not eat it, he is liable to a sacrifice for his oath, even though he is not permitted to eat it, as we have written… And so too I found according to the Rambam, chapter 5 of Hilkhot Shevuot, as I have said, for he writes that one who eats less than an olive-sized portion of neveila or tereifa is liable for taking a [false] oath.
 
The Ran bases himself on the words of the Rambam, who indeed says that the rule of "bound by an oath from Mount Sinai" does not apply to half a measure, whether the oath comes to uphold a Torah mitzva or to cancel it. However, the Rambam does not offer the Ran's explanation, which is far from being obvious; so too the Rambam does not mention the novel position put forward by the Ran that the law in practice is that the person should not fulfill his oath.[4] The Ran bases this on the argument: "For even a Rabbinic prohibition sets aside a Torah commandment in a situation of 'sit and do not act,' all the more so a Torah prohibition. For we do not say to a person: Stand up and actively sin in order to fulfill your oath." This would seem to imply that even if a person took an oath to transgress a Rabbinic prohibition, in which case the oath certainly applies according to the Gemara's conclusion in Yoma, he would be forbidden to fulfill his oath, and this requires further examination. Regarding a Torah prohibition, in any event, and this includes the prohibition of half a measure according to Rabbi Yochanan, the Ran's position is clear. From here it would appear that the Ran does not accept the view of the Ramban that we saw in the previous shiur. The Ramban writes that an inclusive oath applies to cancel a positive commandment, and that theoretically it should apply even to cancel a negative commandment. Only that since in actual practice the law is that the person should sit and not act, and the Halakha is that the person who took the oath should not fulfill it, the oath is considered a vain oath that does not apply ("from the time of the oath it was uttered in vain and does not exist").[5] The Ran maintains that when two obliging but contradictory norms apply, the fact that in practice the halakha instructs us to prefer one of them because of some "technical" preference, e.g., the rule of "sit and do not act," does not turn the other norm into an impossibility which in the context of oaths is defined as a vain oath.
 
We might return to the issue in dispute between the Ramban and the Ran in a later shiur.
 
IV. A prohibition that carries no punishment and a severe prohibition
 
The Ritva as well maintains (like the Ran, and against the Ramban and the Rashba) that according to Rabbi Yochanan an oath not to eat half a measure of neveila takes effect. This position must contend with the problem of "bound by an oath from Mount Sinai" and with the rule that a prohibition does not apply to an item that is already prohibited. The Ritva writes as follows:
 
Since for half a measure there are no lashes, or a sacrifice, or karet, it is not regarded as a situation of "bound by an oath from Mount Sinai" for this purpose, and the prohibition of an oath applies to it, like a more severe prohibition applies to an item that is already subject to a more lenient prohibition. Even one who does not agree about this in general would agree here… that an oath applies to a minute amount, because a more severe prohibition applies to an item that is already prohibited by a more lenient prohibition. For by Torah law half a measure is merely forbidden, whereas an oath is subject to a negative commandment. (22b, 23b)
 
The Ritva does not clarify the relationship that he sees between the rule that a second prohibition does not apply to an item that is already prohibited and the rule of "bound by an oath from Mount Sinai." It may be understood from his words that the very fact that half a measure does not carry any punishment turns it into a prohibition that is not defined as "bound by an oath from Mount Sinai," based on the assumption that is not at all clear that the rule of "bound by an oath from Mount Sinai" relates only to prohibitions that carry punishments. As for the law that a prohibition does not apply to an item that is already prohibited, the prohibition of an oath does apply to a prohibition that does not carry a punishment, based on the rule that a more severe prohibition applies to an item that is already subject to a more lenient prohibition. Though the Halakha has been decided that a more severe prohibition does not apply to an item that is already prohibited by a more lenient prohibition, when there is such an intense gap between the more severe and the more lenient prohibitions, all agree that the new prohibition is sufficiently novel and applies to the old one. It is interesting that the Ran, who at the beginning of his discussion cited earlier brings such a position, but without arguing for the distinction proposed by the Ritva, states that this is a position that is subject to dispute.[6]
 
In any event, according to this position, there is nothing special about the prohibition of half a measure apart from the fact that it carries no punishment. This argument would hold, for example, also with respect to a prohibition that follows from a positive commandment (issur asseh); and the Tosafot reject it for this reason, as they understood that a negative prohibition does not apply to an item that is already prohibited by a prohibition that stems from a positive commandment.
 
V. The impact of the essence of the prohibition of half a measure on the law of "bound by an oath from Mount Sinai" and the law that a second prohibition does not apply to an item that is already prohibited
 
In shiur no. 4 we dealt with the essence of the prohibition of half a measure. We inclined toward the understanding that the argument that "since it could be joined [to form a minimum] it is forbidden food that he is eating," is not the reason for the prohibition, but rather a sign that we have here a prohibition. And we noted a certain understanding according to which this is not a sign that there can be an act of eating with less than an olive-sized measure, but rather a sign that even if there is no act of eating here, the fact that if the person continues what he is doing, there will be an act of eating that carries liability, teaches us that we are dealing with a negative commodity, the very consumption of which is prohibited, even though the Torah's command to the person relates only to an act of eating.[7] Logically, it may be argued that we are dealing with a new explanation for why the rule of "bound by an oath from Mount Sinai" does not apply to half a measure. The Tosafot relate to the rule of half a measure as "a mere prohibition" which is a less significant factor than a prohibition that stems from a positive commandment (issur asseh), for example, despite the fact that even with respect to a prohibition that stems from a positive commandment there is no punishment. It may be explained that in the case of a prohibition that stems from a positive commandment, there is a clear Torah command to the person, while in the case of half a measure there is no command directed to the person (gavra), but only a prohibition on the object (cheftza), and this is not an operative command of the Torah which falls into the category of "bound by an oath from Mount Sinai." So we can explain the words of the Tosafot on p. 22b, s.v. a-hetera: "Since it is a mere prohibition, it is not regarded as 'bound by an oath from Mount Sinai.'" And so it can also be argued regarding the view of the Rambam (Hilkhot Shevu'ot 5:7-8), according to which, as stated, half a measure does not fall into the category of "bound by an oath from Mount Sinai," neither with regard to an oath to fulfill a mitzva, nor with regard to an oath to cancel a mitzva (like the alternative explanation proposed by the Ran regarding his position[8]).
 
However, an examination of the words of the Tosafot, p. 23b, s.v. demoki, paints a more complicated picture. I have not reached a precise understanding of their position, because they don't consistently distinguish between "bound by an oath from Mount Sinai" and the rule that a prohibition does not apply to an item that is already prohibited. But it is possible to conclude from what they say that the notion of "a mere prohibition" with respect to half a measure provides an answer to the limitation of the rule that a prohibition does not apply to an item that is already prohibited, and it explains why, in contrast to a prohibition that is derived from a positive commandment to which an oath or another prohibition do not apply, another prohibition may be applied to the prohibition of half a measure. The explanation for this might be an essential deficiency in the very classification of half a measure as being prohibited, despite the fact that as stated there is a prohibition on the object, and it is possible that this is based on the fact that this is not a prohibition of eating. However, as for "bound by an oath from Mount Sinai," the matter is more complicated. The Tosafot assume as obvious, in contrast to the Rambam, that one cannot take an oath to eat half a measure, since he is bound by an oath from Mount Sinai. This being the case, the Tosafot argue in their last answer, one can also not take an oath not to eat half a measure, not because he is bound by an oath from Mount Sinai, but because this oath does not apply in the positive (this is in accordance with the plain meaning of the Mishna on p. 27a that we have learned, that there is an independent impediment not to swear to cancel a mitzva, and from this follows a problem to swear to uphold a mitzva, because such an oath does not apply in the positive). If so, from the Tosafot on p. 23b, it seems that the formulation according to which half a measure does not fall into the category of "bound by an oath from Mount Sinai" (as they say on 22b and again on 23b) is imprecise, and this is true only with respect to the rule that a second prohibition does not apply to an item that is already prohibited. Further study of their position is required (it should be noted that the Tosafot ha-Rosh here is in doubt about an assertion that is similar to that of the Tosafot on p. 22b – "since it is merely a prohibition, it is not called 'bound by an oath from Mount Sinai").
 
The Pitchei Teshuva (Yoreh De'a 238, no. 1) raises an interesting question that is relevant to our discussion:
 
See the book Rav Peninim on Parashat Noach who writes that there is room for uncertainty regarding whether an oath applies to half a measure with respect to a mixture of meat and milk and with respect to kil'ei ha-kerem, regarding which there is no mention of "eating," for regarding a mixture of meat and milk it is written: "You shall not cook," and regarding kil'ei ha-kerem it is written: "Lest it be forfeited." If so there is room to say that even for a minute quantity there is a negative Torah commandment, only that there are no lashes, as measures are a Halakha that was given to Moshe at Sinai, that for less than an olive-sized measure there are no lashes. If so, an oath does not apply to it. Or perhaps, the Halakha that was given to Moshe at Sinai uproots the verse from its meaning, and there is only a prohibition.
 
According to the first side of this uncertainty, in the case of Torah prohibitions of "eating" there is no negative commandment for half a measure, and for this reason it is not included in "bound by an oath from Mount Sinai." His understanding of such prohibitions is far-reaching: one violates the negative commandment fully even for a half-measure, only there is a Halakha to Moshe at Mount Sinai that there is no punishment. But it may be argued that even if the violation of the negative commandment were only partial, this would suffice for it to fall into the category of "bound by an oath from Mount Sinai," as opposed to prohibitions that are defined as prohibitions of eating, regarding which there is a prohibition without the usual command addressed to the person. However, the accepted approach is that even these two prohibitions are included among the prohibitions of eating.
 
To conclude this shiur, I wish to cite from the Meiri (25a) who presents his own approach in explaining the validity of an oath with respect to half a measure according to Rabbi Yochanan. I have difficulty understanding what he says, and I will leave the task to my readers:
 
Even Rabbi Yochanan only said that because it can be joined, as is explained there, and he who takes an oath about half a measure has already made it clear that he has no intention of eating a full measure, and so he has removed it from a Torah prohibition, since the Torah only forbade it because it can be joined, and he is at the beginning of his eating. This implies that anybody who does not intend this to be the beginning of his eating, but rather intends that his entire eating of the prohibited item should be half a measure, this is not prohibited by Torah law, as this does not fall into the category of eating. So it seems to me.
 
(Translated by David Strauss)  
 
Sources for next shiur: One Who Took An Oath Not to Eat Half a Measure of a Prohibited Item and then Ate a Full Measure.
 
In the previous shiur we dealt with the dispute regarding whether a half-measure of a prohibited item falls into the category of "bound by an oath from Mount Sinai." In this shiur we will discuss the opinions that this case is not subject to the rule of "bound by an oath from Mount Sinai. We will also examine the law in the case where a person took an oath not to eat half a measure, and then ate a full measure; is he now liable twice? In this context see Tosafot ha-Rosh, 24b, in the passage cited below (which relates to the Gemara there which states: "For example, if he said: I swear that I shall not eat dates and forbidden fat; since it takes effect with respect to the dates, it takes effect also with respect to the forbidden fat"); and compare with Rashi, Yoma 73b, last two comments. See also Rambam, Hilkhot Shevuot 5:7, and try to understand his approach.
 
See Mishna 27b, and the Gemara there until "He is not liable until he eats it all," and Rashi, ad loc. What difficulty arises with respect to Rashi? Is it possible to suggest ways to distinguish between the cases under discussion?
 
 
Tosafot Rosh, Shevuot 24b:
"It may be asked: Even without an inclusive oath we find it. For example, where he said: I swear that I shall not eat half an olive-sized measure of fat, regarding which he is not bound by an oath from Mount Sinai, and when he eats an olive-sized measure, he is liable for his oath, since an olive-sized measure includes half an olive-sized measure. And it should have said: According to your reasoning." 
 

[1] This point in itself is stated only in the Gemara in Yoma, but the Rishonim assume that it is accepted by our passage as well.
[2] The Ran's commentary to the Rif in our chapter, 11a in the Alfasi, s.v. avi; his commentary to Nedarim 8a, s.v. ha kamashma lan; his responsa, no. 32.
[3] The Ran contends with the Gemara in Yoma and writes: "That which is stated in Yoma that according to Resh Lakish, since he maintains that it is permitted by Torah law, therefore he liable for a sacrifice for an oath, which implies that if it is not permitted by Torah law, he would not be liable, was stated for the convenience of the matter, because according to Resh Lakish it is permitted by Torah law. But in fact anything that is not subject to an explicit positive or negative commandment, even if it is prohibited by Torah law, as in the case of half a measure according to Rabbi Yochanan, he is liable on its account for a sacrifice for an oath." For those who wish to delve deeper into this matter, the Avnei Milu'im (Responsa, no. 14) proposes another way to reconcile the passage in Yoma according to the Ran.
[4] The Radbaz on halakha 8 decides against the Ran (without mentioning him): "It is preferable that he eat it and not violate his oath; however, if it is possible by way of an opening or regret, we annul the vow for him and open opportunities for him to retract it."
[5] The Ran in his Chiddushim (24a) and in his commentary to the Rif (9b) accepts the Ramban's distinction between the Bavli, which deals with cancelling a negative commandment, and the Yerushalmi, which deals with cancelling a positive commandment, but he does not mention the Ramban's novel idea concerning the oath's not taking effect and the reason for that.
[6] "Since he is not liable for a sacrifice or lashes on account of it, it is a lenient prohibition, and perhaps the Tanna maintains that a more severe prohbition applies to an item forbidden by a more lenient prohibition, as we find in chapter Asara Yuchasin."
[7] For those who are interested in exploring the matter further, see the Maharshal and the Maharsha on the Tosafot, s.v. de-moki (which will be discussed below). Consider whether what we have said helps us to understand the words of the Maharshal.
[8] The Radbaz on halakha 7 explains the position of the Rambam as being similar to that of the Ran (without mentioning the Ran). It is interesting that he presents the difficulty as follows: "I have a difficulty. Since it is prohibited by Torah law, he is bound by an an oath regarding it, as it is written: 'Cursed be he that confirms not the words of this law.'" It may be understood that, according to him, the cited verse is the source of the law of "bound by an oath from Mount Sinai" (see what we wrote in shiur no. 9). But it may also be understood that when we are dealing with an ordinary Torah prohibition, like eating an olive-sized measure of neveila, then the source of the law of "bound by an oath" is the verse that forbids neveila. Only with regard to the prohibition of half a measure, which as stated is not based on an explicit command to the person, does the Radbaz require the verse of "Cursed be he that confirms not," which according to his understanding is the source for the general concept of "bound by an oath from Mount Sinai" regarding all that the Torah in practice commands him, including "a mere prohibition" like half a measure, as we have explained it. According to this, the Radbaz counters our explanantion and says that we still need the principle of the Ran.